TORONTO - Thousands of public-sector union members are protesting in a park near the Ontario Liberal leadership convention as they prepare for a march planned for later today.

Charter buses dropped off crowds of demonstrators — many of them public school teachers — in downtown Toronto, steps away from where delegates are voting for the party’s next leader and the province’s new premier.

The crowd roared as labour leaders took to the stage and condemned the government’s decision to impose contracts on public school teachers, saying it violated workers’ democratic rights.

Sid Ryan, president of the Ontario Federation of Labour, told protesters to voice their disapproval for the leadership candidates on social media.

The head of the union representing public elementary school teachers says he wants the next premier to mend the government’s relationship with public sector unions.

Ken Coran says the next government needs to be fair, respectful and democratic.

Picketers got an early start this morning, with dozens posted outside the convention despite the chilly weather.

One of the province’s largest labour groups says thousands of people drawn from public sector unions, community groups and others looking to send a message to delegates and the new premier they pick will march to the convention site this afternoon.

The OFL says more than 100 unions and community organizations are expected to attend and show opposition to anti-strike legislation and budget cutbacks by the Liberal government.

Demonstrators seem particularly angered over the province’s move to impose contracts on public school teachers, which many are calling an attack on democracy.

The OFL says 131 buses have arrived in town carrying demonstrators from all corners of the province.